DESCRIPTION (Applicant's abstract): Social deficits may be life long problems for a substantial number of children with ADHD. Almost none of the interventions commonly used to improve children's peer relations have used parents to aid the generalization of skills taught or have focused on the development of best friends. The effect sizes for school based interventions average .19, while our effect size ranges from .93 to 1.34 when these two features are included. The present project addresses the question: Does parent-assisted children's social skills treatment enhance peer acceptance and best friendships over the effects of optimally titrated stimulant medication? The plan is to diagnose children meeting DSM-IV criteria for ADHD and having problems with peer relationships. Treatment will be superimposed over stimulant medication titrated to an optimal dosage for ADHD symptoms in a procedure similar to that used by the NIMH Multimodal Treatment Study for Children with ADHD, (MTA study) (Greenhill et al., 1996). Subjects will be assigned randomly to one of three groups of 50 subjects each: Parent Assisted Social Skills Treatment (SST), Placebo Psychosocial Treatment (PPT), Wait list (WL). An after-school care setting will facilitate peer sociometric measurement and 16-week follow-up. Outcome will be analyzed for individual, teacher, and parent based measures and peer sociometric measurement as well as an overall profile of measures. Measures found to predict treatment response will also be employed and analyzed in the proposed project. Long term goals of the project: (1) to adapt the treatment and medication package for use in community settings; (2) to develop a community-based algorithm for medication and combination of modules of parent-assisted social skills training to remediate the social deficits of children with ADHD; and, (3) to demonstrate the long-term effectiveness of parent-assisted social skills training on ADHD children who have established deficits in making and/or keeping friends.